Abstract Infertile couples are increasingly turning to Assisted Reproductive Technologies (ART) to treat their infertility. Of growing concern is that ART-conceived children are at increased risk for specific loss-of-imprinting disorders, congenital malformations, growth restriction, preeclampsia as well as postnatal cardiac and metabolic disorders. Given the difficulty of conducting studies using human embryos, a mouse model system, which anticipated some risks associated with ART, will be used to assess the effects of ART on placental morphology, imprinted gene regulation, growth, metabolic, cardiac and behavioral phenotypes of the offspring, and gene expression and chromatin structure genome-wide. Specific Aim 1 will assess the phenotypes, including growth, behavior metabolism and cardiovascular function, of ART-offspring in comparison to naturally-conceived controls. We will also interrogate imprinted gene regulation and gene expression, DNA methylation and chromatin structure using gene-specific and high throughput analyses. Moreover, the design of this aim will enable us to isolate, phenotype and match placenta to offspring to determine whether the placental phenotype can accurately predict health of in vitro fertilization (IVF)-derived offspring. Because we have previously reported a low frequency of epigenetic errors in multiple tissues of IVF-conceived offspring, we hypothesize that the germline cells also harbor epigenetic mutations. In Specific Aim 2, we will test this hypothesis by determining whether aberrant phenotypes observed in IVF offspring are transmitted to subsequent generations and, if so, assess the mechanism of this transmission. The result from these experiments will provide a trove of information regarding the linkage between epigenetic changes and health of offspring conceived by ART and whether placental phenotyping can predict offspring health. Our findings may also suggest experimental modifications to ART procedures that can improve offspring outcomes. !